1. Field of the Invention
The present invention relates to a semiconductor device. The present invention particularly relates to a semiconductor device capable of wirelessly communicating data, a so-called IC chip (also referred to as an ID chip or a transponder) for RFID (radio frequency identification).
Note that a semiconductor device described in this description refers to a general device capable of functioning by utilizing semiconductor characteristics.
2. Description of the Related Art
In recent years, it is called ubiquitous information society that an environment in which it is possible to access an information network anytime and anywhere has been put into place. In such environment, an individual identification technique in which an ID (individual identification number) is given to an individual object to clarify records of the object so that it is useful for production, management, and the like has been researched for practical use. Among them, a semiconductor device (hereinafter referred to as a semiconductor device, and also referred to as an ID chip, an IC chip, or a transponder) using an RFID (radio frequency identification) technique, which wirelessly communicates data with an external communication device (hereinafter referred to as a communication device, and also referred to as a reader/writer, a controller, or an interrogator) has begun to be widely used.
A semiconductor device receives a wireless signal transmitted from a communication device with an antenna. Being an AC voltage signal (hereinafter referred to as an AC signal), the wireless signal is converted into a DC voltage signal (hereinafter referred to as a DC signal) by a rectifier circuit for rectification. The DC signal is inputted to a constant voltage circuit (also referred to as a regulator or a power supply circuit) so that a power supply voltage Vdd is generated. The power supply voltage Vdd generated in the constant voltage circuit is applied to a plurality of circuits included in the semiconductor device.
In the semiconductor device, it is important to supply a stable voltage to the constant voltage circuit for stable operation of the semiconductor device. As an example, Non-Patent Document 1 discloses a structure in which a capacitor is provided for applying a stable voltage to the constant voltage circuit (Non-Patent Document 1: Ray Barnett, Ganesh Balachandran, Steve Lazar, Brad Kramer, George Konnail, Suribhotla Rajasekhar, two Vladimir Drobny, “A Passive UHF RFID Transponder for EPC Gen 2 with −14 dBm Sensitivity in 0.13 μm CMOS” ISSCC, 32 8, PP582-583, pp 623, 2007).    [Non-Patent Document 1] Ray Barnett, Ganesh Balachandran, Steve Lazar, Brad Kramer, George Konnail, Suribhotla Rajasekhar, Vladimir Drobny, “A Passive UHF RFID Transponder for EPC Gen 2 with −14 dBm Sensitivity in 0.13 μm CMOS” ISSCC, 32 8, PP 582-583, pp 623, 2007